JP4465126B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly to an active matrix liquid crystal display device in which a switching element is provided for each pixel and a manufacturing method thereof.
[0002]
[Prior art]
The active matrix type liquid crystal display device has a structure as shown in FIG.
In FIG. 1A, a thin film transistor (TFT) 103 is formed as an active element on a first glass substrate 101 through a base insulating film 102. The thin film transistor 103 includes a semiconductor layer 103a formed on the base insulating film 102, a gate electrode 103c formed on the center of the semiconductor layer 103a via a gate insulating film 103b, and a gate electrode of the semiconductor active layer 103a. A drain layer 103d and a source layer 103e are formed on both sides of the 103c.
[0003]
A data wiring 105, a gate wiring 106, and a source wiring 107 are formed on the first interlayer insulating film 104 covering the thin film transistor 103, and a data wiring 105, a gate wiring 106, and a source wiring 107 are further formed on the first interlayer insulating film 104. A covering second interlayer insulating film 108 is formed. The gate wiring 106 is connected to the gate electrode 103c through the first hole 104a of the first interlayer insulating film 104, the data wiring 105 is connected to the drain layer 103d through the second hole 104b of the first interlayer insulating film 104, and The source wiring 107 is connected to the source layer 103e through the third hole 104c of the first interlayer insulating film 104.
[0004]
A pixel electrode 109 is formed on the second interlayer insulating film 108, and the pixel electrode 109 is connected to the source wiring 107 through the hole 108 a of the second interlayer insulating film 108.
A circuit diagram of the thin film transistor 103, the pixel electrode 109, the data wiring 105, the gate wiring 106, and the source wiring 107 as described above is as shown in FIG.
On the other hand, a common electrode 112 made of a transparent conductive material is formed on the entire display area of the second glass substrate 111, and a color filter and a black matrix 113 are formed between the common electrode 112 and the second glass substrate 111. Has been.
[0005]
The first glass substrate 101 and the second glass substrate 111 are fixed in a state where the pixel electrode 109 and the common electrode 112 are opposed to each other with a space therebetween, and the liquid crystal 110 is sandwiched between the substrates 101 and 111. ing.
A pixel driving circuit (not shown) is connected to the thin film transistor 103 and the counter electrode 112 as described above, and the thin film transistor 103 is controlled by the pixel driving circuit.
[0006]
For example, a driving voltage of ± 5 V as shown in FIG. 1C is applied to the pixel electrode 109 by a pixel driving circuit, and a 0 V voltage wiring is connected to the common electrode 112. The liquid crystal 110 is driven by a change in electric field between the pixel electrode 109 and the common electrode 112. Therefore, a liquid crystal driving power source of 10 V or more is required to operate the liquid crystal 110 sufficiently.
[0007]
[Problems to be solved by the invention]
Incidentally, in the liquid crystal display device, a peripheral circuit is provided in addition to the display unit and the pixel driving circuit, and the voltage of the power source connected to the IC used for the peripheral circuit is as low as 3.3 V, for example.
Therefore, in the liquid crystal display device, two power sources are required for driving the peripheral circuit IC and driving the pixel driving circuit, respectively.
[0008]
In the future, in order to reduce the cost of the liquid crystal display device, it is advanced to manufacture a peripheral circuit using a thin film transistor on the same substrate as the display portion and the pixel driving circuit.
In such a case, as described above, since the voltages required for driving the peripheral circuit and the liquid crystal are different from each other, a high voltage thin film transistor and two power sources are required, and it is difficult to reduce power consumption.
[0009]
An object of the present invention is to provide a liquid crystal display device capable of reducing the voltage required for driving the liquid crystal and a method for manufacturing the same.
[0010]
[Means for Solving the Problems]
  The above-described problem is that a pixel electrode and an individual counter electrode are formed at an interval for each pixel region between the first substrate and the second substrate, the first switching element is connected to the pixel electrode, and the individual counter electrode A second switching element is connected toFurther, a voltage V is applied to the pixel electrode by inputting a pulse voltage out of phase with the first switching element and the second switching element. ₀ When 0V is applied, 0V is applied to the individual counter electrode, and when 0V is applied to the pixel electrode, a voltage V is applied to the individual counter electrode. ₀ Connected pixel drive circuit to applyThis is solved by a liquid crystal display device having a configuration. The first switching element and the second switching element are, for example, thin film transistors.
[0011]
The individual counter electrode may be formed on the insulating film on the first substrate on which the pixel electrode is formed via a support portion, or may be formed on the second substrate. When the individual counter electrode is formed on the second substrate, the second switching element connected to the individual counter electrode may be formed on the second substrate, or may be formed on the first substrate. Also good. When the second switching element is formed on the first substrate and the individual counter electrode is formed on the second substrate, the connection between the second switching element and the individual counter electrode is connected via a conductive column. .
[0012]
The individual counter electrode and the pixel electrode may be opposed to each other in a direction perpendicular to the surface of the first substrate.
As described above, according to the present invention, the voltage V V is applied to the first switching element connected to the pixel electrode and the second switching element connected to the individual counter electrode, respectively.₀Is input with the phase shifted, the liquid crystal sealed between the electrodes is ± V₀Thus, the operation of the liquid crystal is the same as the conventional one. However, since the voltage of the power source required for driving the liquid crystal is half that of the prior art, the voltage required for driving the liquid crystal driving circuit can be lowered.
[0013]
Therefore, the power source connected to the peripheral circuit and the liquid crystal driving circuit can be shared. As a result, the voltage applied to the liquid crystal driving circuit is reduced, so that the power consumption can be reduced and the cost can be reduced.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
2-5 is sectional drawing which shows the formation process of the display part of the liquid crystal display device which concerns on 1st Embodiment of this invention.
[0015]
The process until the thin film transistor as shown in FIG.
First, on the insulating TFT substrate 1 made of glass, the base insulating film 2 is made of SiO.₂After the film is formed to a thickness of 200 nm by plasma CVD (P-CVD), an amorphous silicon (a-Si) film having a thickness of 50 nm is formed on the base insulating film 2 by P-CVD.
[0016]
Subsequently, after the a-Si film was heated at 450 ° C. for 2 hours in a nitrogen atmosphere, 300 mJ / cm²The a-Si film is polycrystallized into a polycrystalline silicon (semiconductor) film 3 by irradiating the laser beam with the power of.
Further, the polycrystalline silicon film 3 is patterned by photolithography to leave the polycrystalline silicon film 3 in the active element formation regions of the display region, the peripheral circuit region, and the liquid crystal driving circuit region defined on the TFT substrate 1. Here, in the display region having a plurality of pixel regions A, as shown in FIG. 2A, the polycrystalline silicon film 3 is left in two active element regions near both sides of each pixel region A.
[0017]
Next, on the polycrystalline silicon film 3 and the base insulating film 2, SiO₂A gate insulating film 4 is formed by P-CVD, and the gate insulating film 4 is annealed at a temperature of 450 ° C. for 2 hours in a nitrogen atmosphere. Further, an aluminum film for forming the gate electrode 5 is formed on the gate insulating film 4 to a thickness of 300 nm by sputtering.
After forming a gate-shaped resist pattern (not shown) on the aluminum film, the resist pattern is used as a mask and Cl₂And BCl_ThreeAnd SiCl_FourThe aluminum film is dry-etched using the mixed gas, thereby forming the gate electrode 5. Subsequently, using the resist pattern as a mask, the gate insulating film 4 is made CF._FourDry etching is performed using a gas. Thereby, the gate electrode 5 and the gate insulating film 4 are formed in a region passing through the center of the polycrystalline silicon film 3 in the active element region.
[0018]
Next, as shown in FIG. 2B, the polycrystalline silicon film 3 is doped with impurities using the gate electrode 5 as a mask. For example, in the pixel region A, the polycrystalline silicon film 3 has PH_ThreeAnd H₂Phosphorus is doped by ion implantation using a mixed gas of Phosphorus ion implantation is performed twice, for example. The first time is an acceleration energy of 90 keV and a dose of 1 × 10.¹⁴cm^-2Conditions, second time acceleration energy 10 keV, dose amount 4 × 10¹⁵cm^-2The condition is set. After that, after annealing the polycrystalline silicon film 3 in a nitrogen atmosphere under a substrate temperature of 380 ° C. for 2 hours, 200 mJ / cm²Impurities are activated by irradiating a laser beam with a power of. Thereby, a source layer 3s having an LDD structure and a drain layer 3d having an LDD structure are formed in regions on both sides of the gate electrode 5 in the polycrystalline silicon film 3 in each active element region.
Thus, a thin film transistor (TFT) formation process is completed, and a first TFT 6 and a second TFT 7 exist in each pixel area A of the display area.
[0019]
Similarly, an n-type TFT and a p-type TFT are formed in the peripheral circuit region and the liquid crystal driving circuit. When a p-type TFT is formed, the polycrystalline silicon film on both sides of the gate electrode of the polycrystalline silicon film has B₂H₆And H₂Is doped with boron by ion implantation. The polycrystalline silicon film into which boron has been implanted is annealed under the same conditions as described above and irradiated with laser light.
[0020]
Next, as shown in FIG. 2C, a first interlayer insulating film 8 is formed on the TFTs 6 and 7 and the base insulating film 2 by a plasma CVD (P-CVD) method. The first interlayer insulating film 8 is formed of silicon oxide (SiO 2 with a thickness of 30 nm in order from the bottom.₂) Silicon nitride (Si) with a thickness of 370 nm_ThreeN_FourIt is constructed by growing a film.
[0021]
Subsequently, the first interlayer insulating film 8 is annealed in a nitrogen atmosphere under the condition of a substrate temperature of 380 ° C. for 2 hours to densify the first interlayer insulating film 8.
Further, the first interlayer insulating film 8 is patterned by photolithography to form first to third contact holes 8a to 8c on the gate electrode 5, the source layer 3s, and the drain layer 3d, respectively. When the first to third contact holes 8a to 8c are formed, the silicon oxide film constituting the first interlayer insulating film 8 is HF and NH._FourAnd H₂The silicon nitride film which is etched using O 2 and forms the first interlayer insulating film 8 is CF_FourAnd O₂Etching is performed using a mixed gas of
[0022]
Next, after removing the resist pattern, a metal film is formed by sputtering in the first to third contact holes 8 a to 8 c and on the first interlayer insulating film 8. The metal film has, for example, a three-layer structure in which a titanium layer with a thickness of 100 nm, an aluminum layer with a thickness of 200 nm, and a titanium layer with a thickness of 100 nm are sequentially formed from the bottom.
Subsequently, as shown in FIG. 3A, a metal film is patterned by a photolithography method, whereby the data wiring connected to the drain layer 3d through the first hole 8a on the first TFT 6 in the pixel region A. 9a, a gate wiring 9b connected to the gate electrode 5 through the second hole 8b, and a source wiring 9c connected to the source layer 3s through the third hole 8c are formed on the first interlayer insulating film 8, respectively. At the same time, on the second TFT 7 in the pixel region A, the counter data wiring 10a connected to the drain layer 3d through the first hole 8a, and the gate wiring 10b connected to the gate electrode 5 through the second hole 8b Then, a source wiring 10 c connected to the source layer 3 s through the third hole 8 c is formed on the first interlayer insulating film 8.
[0023]
Next, as shown in FIG. 3B, the second interlayer insulating film 11 made of silicon nitride covering the data wiring 9a, the counter data wiring 10a, the gate wirings 9b and 10b, and the source wirings 9c and 10c is formed by P-CVD. A thickness of 200 nm is formed on the interlayer insulating film 8 by the method.
Further, the second interlayer insulating film 11 is patterned by photolithography to form a first via hole 11 a on the source wiring 9 c connected to the first TFT 6. The dry etching for forming the first via hole 11a is CF_FourAnd O₂The mixed gas is used.
[0024]
Subsequently, an ITO film, which is a transparent conductive material, is formed to a thickness of 100 nm by sputtering in the first via hole 11a and on the second interlayer insulating film 11. Then, the ITO film is separated for each pixel region A by patterning by photolithography. In the pixel region A, the ITO film becomes a pixel electrode 12 having a size of, for example, 35 nm × 100 nm, and is connected to the source wiring 9c through the first via hole 11a.
[0025]
Next, as shown in FIG. 3 (c), a photosensitive polyimide (organic resin) film 13 is spin-coated on the pixel electrode 12 and the second interlayer insulating film 11 to a thickness of 200 nm, and then polyimide. The film 13 is exposed and developed to form an opening 13 a on the source wiring 10 c connected to the second TFT 7. A resist film may be used instead of the polyimide film 13.
[0026]
Further, using the polyimide film 13 as a mask, the second interlayer insulating film 11 under the opening 13a is etched to form the second via hole 11b on the source wiring 10c. The etching of the second interlayer insulating film 11 is CF_FourAnd O₂The mixed gas is used. The opening 13a is formed on the source line 10c separately for each pixel region A.
[0027]
Thereafter, an ITO film having a thickness of 100 nm is formed in the opening 13 a, the second via hole 11 b, and the polyimide film 13.
Subsequently, as shown in FIG. 4A, the ITO film is patterned by a photolithography method to form the individual counter electrode 14 facing the pixel electrode 12, and the individual counter electrode 14 is opened to the opening 13a and the second electrode. To the source wiring 10c through the via hole 11b. The ITO film in the opening 13 a and the second via hole 11 b functions as a conductive support portion 14 a that supports the individual counter electrode 14.
[0028]
For example, as shown in FIG. 6, the individual counter electrode 14 has a rectangular shape facing the pixel electrode 12 through the polyimide film 13, and the support portion 14 a has a wall shape along one side of the individual counter electrode 14. ing.
Thereafter, as shown in FIG. 4B, when the polyimide film 13 is selectively removed with a solvent, a gap is formed between the pixel electrode 12 and the individual counter electrode 14 and a conductive support portion 14a appears. .
[0029]
Next, as shown in FIG. 5, a counter substrate 17 made of glass having a black matrix 15 and a color filter 16 formed on the upper surface is prepared, and the counter substrate 17 and the TFT substrate 1 are bonded together. The bonding is performed on the outer peripheral region of the counter substrate 17 and the TFT substrate 1 via a sealant (not shown), and the color filter 16 and the pixel electrode 12 are opposed to each other and the color filter 16 is very close to the individual counter electrode 14. Or stuck together.
[0030]
A liquid crystal 18 is sealed between the TFT substrate 1 and the counter substrate 17 before or after the substrates are bonded together.
The pixel electrode 12, the first TFT 6, the individual counter electrode 14, and the second TFT 7 in the pixel region A of the liquid crystal display device formed by the above steps are connected to the pixel driving circuit 20 as shown in FIG. The
[0031]
Then, as shown in FIG. 7B, a data signal having a voltage of 0 V or 5 V or a counter data signal is applied to the first TFT 6 and the second TFT 7. That is, the pixel drive circuit 20 connected to the power supply of 5 V voltage inputs 5 V to the pixel electrode 12 through the data wiring 9 a by inputting the pulse voltage with the phase shifted to the first TFT 6 and the second TFT 7. When a voltage of 0 V is applied to the individual counter electrode 14 through the counter data wiring 10a, and when a voltage of 0 V is applied to the pixel electrode 12 through the data wiring 9a, the voltage is applied individually through the counter voltage wiring 10a. A voltage of 5 V is input to the electrode 14. The time difference between the data signal input to the first TFT 6 and the counter data signal input to the second TFT 7 is the same as the pulse width of those pulse signals.
[0032]
As a result, the liquid crystal 18 between the individual counter electrode 14 and the pixel electrode 12 is placed in an AC electric field of ± 5 V as shown in FIG.
Accordingly, the voltage required for the liquid crystal drive circuit can be reduced to half of the conventional voltage, and as a result, the peripheral circuit and the liquid crystal drive circuit that require separate power supplies can be shared by only one power supply. It becomes like this. As a result, it is possible to reduce the withstand voltage of the thin film transistor and reduce the power consumption, and the cost can be reduced as one power source.
[0033]
The individual counter electrode 14 described above is supported only by the support portion 4a on the source wiring 10c on the second TFT 7, but when it is desired to reliably prevent the individual counter electrode 14 from being bent, it is shown in FIG. As described above, an insulating spacer 19 may be sandwiched between the pixel electrode 12 and the individual counter electrode 14 above the first TFT 6. For example, after the polyimide film 13 is removed as shown in FIG. 4B, photosensitive polyimide is again applied on the pixel electrode 14 and the second interlayer insulating film 13, and the polyimide is exposed and developed. Therefore, this is used as the spacer 19 while leaving a part between the pixel electrode 12 and the individual counter electrode 14.
(Second Embodiment)
In the first embodiment, the support portion 14a for supporting the individual counter electrode 14 is formed along the source wiring 10c of the second TFT 7 as shown in FIG. As shown in (c), not only one side of the rectangular individual counter electrode 14 but also two or three sides may be formed. 9A shows the upper surface of the individual counter electrode 14 on which the support portions 14a and 14c are formed along the two adjacent sides, and FIG. 9B shows the support portions 14a, 14b and the support portions 14a and 14b along the three adjacent sides. FIG. 9C shows the upper surface of the individual counter electrode 14 on which the support portions 14a and 14b are formed along the two opposing sides, respectively.
[0034]
Next, a process of forming the support portions 14a and 14b on the portions along two parallel sides of the individual counter electrode 14 as shown in FIG. 9C will be described.
First, the processes from the formation of the base insulating film 2 to the formation of the second interlayer insulating film 11 are the same as those in the first embodiment.
Next, as shown in FIG. 10A, the second interlayer insulating film 11 is patterned by a photolithography method, and the source wirings 9c and 10c connected to the first and second TFTs 6 and 7, respectively. After forming the first and second via holes 11a and 11b, the pixel electrode 12 electrically connected to the first TFT 6 through the first via hole 11a is formed on the second interlayer insulating film 11, and thereafter Then, a photosensitive polyimide film 13 is formed on the pixel electrode 12 and the second interlayer insulating film 11. Further, the photosensitive polyimide film 13 is exposed and developed to partially remove the polyimide in and on the second via hole 11b to form the first opening 13a and above the first TFT 6. A second opening 13b is formed.
[0035]
Next, after forming an ITO film on the polyimide film 13 and in the first and second holes 13a and 13b, the ITO film is patterned by a photolithography method, so that an ITO film is formed as shown in FIG. When the film is separated for each pixel region A and left in the first and second openings 13a and 13b, the pixel region A has individual first and second support portions 14a and 14b on the lower surface. Electrode 14 is formed. In this case, the individual counter electrode 14 is electrically connected to the source layer 3s of the second TFT via the first support portion 14a and the source wiring 10c. Note that the second support portion 14 b is insulated from the first TFT 6 by the second interlayer insulating film 11.
[0036]
Thereafter, when the polyimide 13 is removed with a solvent, the individual counter electrode 14 is not only the first support portion 14a on the source wiring 10c on the second TFT 7, as shown in FIG. It is supported by a second support portion (spacer) 14b on the TFT 6 of one.
After that, as shown in FIG. 11B, as in the first embodiment, the counter substrate 17 and the TFT substrate 1 are formed using the counter substrate 17 having the black matrix 15 and the color filter 16 formed on the upper surface. Stick together. A liquid crystal 18 is sealed between the TFT substrate 1 and the counter substrate 17 before or after the substrates are bonded together.
[0037]
In the liquid crystal display device as described above, the individual counter electrode 14 is supported not only on the second TFT but also on other portions by the support portions 14a and 14b, so that the deformation of the individual counter electrode 14 can be prevented more reliably. The In such a pixel region A, the circuit diagram shown in FIG. 7A is obtained, and the signal shown in FIG. 7B is input.
(Third embodiment)
In the above-described embodiment, the individual counter electrode is formed on the TFT substrate side, but may be formed on the counter substrate side as shown in FIG.
[0038]
In FIG. 12, as in the first embodiment, a base insulating film 2 is formed on a TFT substrate 1 made of glass, and a first interlayer insulating film 8 is covered on the base insulating film 2. One TFT 6 is formed for each pixel region. The first TFT 6 includes a gate electrode 5 formed on the semiconductor layer 3 via the gate insulating film 4, an LDD structure drain layer 3 d formed on both sides of the gate electrode 5 in the semiconductor layer 3, and an LDD structure. Source layer 3s. The drain layer 3d is connected to the data wiring 9a on the first interlayer insulating film 8 through the contact hole 8a, the gate electrode 5 is connected to the gate wiring 9b on the first interlayer insulating film 8 through the contact hole 8b, and the source The layer 3s is connected to the source wiring 9s on the first interlayer insulating film 8 through the contact hole 8c. A second interlayer insulating film 11 is formed on the data wiring 9 a, the gate wiring 9 b, the source wiring 9 c and the first interlayer insulating film 8, and a pixel electrode 12 is formed on the second interlayer insulating film 11. Has been. The pixel electrode 12 is connected to the source wiring 9 c through a via hole 11 a formed in the second interlayer insulating film 11.
[0039]
On the other hand, a base insulating film 21 is formed on the counter substrate 17, and a second TFT 23 covered with a first interlayer insulating film 22 is formed on the base insulating film 21 for each pixel region. The second TFT 23 includes a gate electrode 25 formed on the semiconductor layer 26 via the gate insulating film 24, an LDD structure drain layer 26d formed on both sides of the gate electrode 25 in the semiconductor layer 26, and an LDD structure. A source layer 26s is provided. The drain layer 26d is connected to the counter data wiring 27a on the first interlayer insulating film 22 through the contact hole 22a, the gate electrode 25 is connected to the gate wiring 27b on the first interlayer insulating film 22 through the contact hole 22b, and The source layer 26s is connected to the source wiring 27c on the first interlayer insulating film 22 through the contact hole 22c. A second interlayer insulating film 28 is formed on the counter data wiring 27 a, the gate wiring 27 b, the source wiring 27 c, and the first interlayer insulating film 22, and the individual counter electrode 29 is formed on the second interlayer insulating film 28. Is formed. The individual counter electrode 29 is connected to the source wiring 27 c through a via hole 28 a formed in the second interlayer insulating film 28.
[0040]
The counter substrate 17 and the TFT substrate 1 described above are bonded together with the individual counter electrode 29 and the pixel electrode 12 facing each other with a gap therebetween, and the liquid crystal 18 is sealed between the pixel electrode 12 and the individual counter electrode 29. .
The pixel region of the liquid crystal display having the above structure has a circuit configuration as shown in FIG. 7A, and a voltage as shown in FIG. 7B is applied to the pixel electrode 12 and the individual counter electrode 29. Is done. Therefore, also in the liquid crystal display device having the structure shown in FIG. 12, a 5V power source can be used as the power source of the pixel driving circuit 20.
[0041]
Next, steps required until the structure shown in FIG.
First, as shown in FIG. 13A, a base insulating film 2 is formed on a first insulating film substrate 1 made of glass, and further, the first insulating film 2 is formed under the same conditions and method as in the first embodiment. The first TFT 6 is formed, and a first interlayer insulating film 8 covering the first TFT 6 is formed on the base insulating film 2. Here, TFTs connected to the individual counter electrodes are not formed.
[0042]
Subsequently, the first interlayer insulating film 8 is patterned to form first to third contact holes 8a to 8c on the gate electrode 5, the source layer 3s, and the drain layer 3d of the first TFT 6, respectively. Further, a metal film is formed on the first interlayer insulating film 8, and the metal film is patterned by a photolithography method, whereby the data wiring 9a connected to the drain layer 3d through the first contact hole 8a, and the first A gate wiring 9b connected to the gate electrode 5 through the second contact hole 8b and a source wiring 9c connected to the source layer 3s through the third contact hole 8c are formed.
[0043]
Thereafter, as shown in FIG. 13B, a second interlayer insulating film 11 made of silicon nitride is formed on the first interlayer insulating film 8 under the same conditions as in the first embodiment. The second interlayer insulating film 11 is patterned to form a via hole 11b on the source wiring 9c, and a pixel electrode 12 connected to the source wiring 3s through the via hole 11b is formed on the second interlayer insulating film 11. .
[0044]
Each condition until the pixel electrode 12 is formed on the TFT substrate 1 is the same as that in the first embodiment except that the second TFT is not formed.
The individual counter electrodes on the counter substrate disposed to face the TFT substrate 1 are formed through the processes shown in FIGS. 14 (a) to 14 (c).
First, steps required until a structure shown in FIG.
[0045]
On the second insulating film substrate 17 made of glass, SiO having a thickness of 200 nm as the base insulating film 21₂Then, an amorphous silicon film having a thickness of 50 nm is formed on the base insulating film 21 by the P-CVD method. Subsequently, 300 mJ / cm while heating the a-Si film at 450 ° C. for 2 hours in a nitrogen atmosphere.²The a-Si film is polycrystallized into a polycrystalline silicon (semiconductor) film by irradiating laser light with a power of.
[0046]
Further, the polycrystalline silicon film is patterned by a photolithography method so as to be separated for each active element region of the display region defined in the second insulating film substrate 17 to leave the polycrystalline silicon film 26.
Next, a SiO 2 film is formed on the polycrystalline silicon film 26 and the base insulating film 21.₂A gate insulating film 24 is formed by P-CVD, and the gate insulating film 24 is annealed at a temperature of 450 ° C. for 2 hours in a nitrogen atmosphere. Further, an aluminum film having a thickness of 300 nm is formed on the gate insulating film 24 by sputtering.
After forming a gate-shaped resist pattern on the aluminum film, the resist pattern is used as a mask and Cl₂And BCl_ThreeAnd SiCl_FourThe aluminum film is dry-etched using the mixed gas, thereby forming the gate electrode 25 made of the aluminum film. Subsequently, using the resist pattern as a mask, the gate insulating film 24 is CF_FourDry etching is performed using a gas. Thereby, the gate electrode 25 and the gate insulating film 24 are formed in a region passing through the center of the polycrystalline silicon film 26 in each active element region.
[0047]
Further, impurities are ion-implanted into the polycrystalline silicon film 26 using the gate electrode 25 as a mask to form an LDD structure source layer 26 s and an LDD structure drain layer 26 d in the polycrystalline silicon film 26 on both sides of the gate electrode 25. To do. Impurity ion implantation conditions are the same as in the first embodiment.
Thus, the formation process of the second TFT 23 is completed.
[0048]
Next, a first interlayer insulating film 22 covering the second TFT 23 is formed on the base insulating film 21 by plasma CVD (P-CVD). The first interlayer insulating film 22 is made of silicon oxide (SiO 2 with a thickness of 30 nm.₂) Silicon nitride (Si) with a thickness of 370 nm_ThreeN_Four) It has a structure in which films are grown in order from the bottom.
Subsequently, the first interlayer insulating film 22 is annealed in a nitrogen atmosphere at a substrate temperature of 380 ° C. for 2 hours.
[0049]
Next, the second interlayer insulating film 22 is patterned by photolithography to form first to third contact holes 22a to 22c on the gate electrode 25, the source layer 26s and the drain layer 26d, respectively.
Further, after removing the resist pattern, a metal film is formed by sputtering in the first to third contact holes 22a to 22c and on the first interlayer insulating film 22. The metal film has, for example, a three-layer structure in which a titanium layer having a thickness of 100 nm, an aluminum layer having a thickness of 200 nm, and a titanium layer having a thickness of 100 nm are sequentially formed from the bottom.
[0050]
Subsequently, the metal film is patterned by photolithography to connect the counter data wiring 27a connected to the drain layer 26d through the first hole 22a of the second TFT 23 and the gate electrode 25 through the second hole 22b. On the first interlayer insulating film 22, a gate wiring 27b to be connected and a source wiring 27c connected to the source layer 26s through the third hole 22c are formed.
[0051]
Next, steps required until a structure shown in FIG.
First, a silicon nitride film is formed to a thickness of 200 nm on the first interlayer insulating film 22 by the P-CVD method as the second interlayer insulating film 30 covering the counter data wiring 27a, the gate wiring 27b, and the source wiring 27c. .
Thereafter, a chromium film having a thickness of 100 nm is formed on the second interlayer insulating film 30 by sputtering, and further, the black film 31 surrounding the pixel region is formed by patterning the chromium film.
[0052]
Thereafter, a third interlayer insulating film 32 made of silicon nitride is formed on the black matrix 31 and the second interlayer insulating film 30 to a thickness of 200 nm by P-CVD, and further, red, green having a thickness of 800 nm. A color filter 33 having a blue multilayer structure is formed.
Next, steps required until a structure shown in FIG.
[0053]
When the color filter 33 is patterned for each of red, green, and blue, an opening 33a is simultaneously formed on the counter data wiring 27c, and the second and third interlayer insulating films 30 and 32 under the opening 33a are patterned. As a result, a via hole 28a is formed on the source wiring 27c.
Next, an ITO film having a thickness of 100 nm is formed in the opening 33a, the via hole 28a, and the third interlayer insulating film, and then the ITO film is patterned by a photolithography method to be separated between the pixel regions. An individual counter electrode 29 is formed. The individual counter electrode 29 is connected to the source line 27c through the opening 33a and the via hole 28a.
[0054]
Next, as shown in FIG. 15, the TFT substrate 1 and the counter substrate 17 are bonded together so that the pixel electrode 12 and the individual counter electrode 29 face each other with a gap therebetween. The bonding is performed between the outer peripheral region of the TFT substrate 1 and the outer peripheral region of the counter substrate 17 via a sealing material (not shown), and the liquid crystal 18 is placed in the gap before or after the TFT substrate 1 and the counter substrate 17 are bonded. Enclosed.
[0055]
Also in the liquid crystal display device having the pixel structure as described above, a circuit configuration similar to that of FIG. 7A is obtained as in the first and second embodiments, and the first TFT 6 and the second TFT 23 are provided. A voltage as shown in FIG. 7B is applied.
In addition, since the pixel electrode 12 and the individual counter electrode 29 are formed on different substrates, when the substrates are attached, the interval between the individual counter electrode 29 and the pixel electrode 12 can be freely set. Bonding of substrates becomes easy.
(Fourth embodiment)
The liquid crystal display device according to this embodiment has a structure in which an individual counter electrode is formed on the counter substrate side, and a thin film transistor for driving the individual counter electrode is formed on the TFT substrate. A description will be given with reference to FIGS.
[0056]
First, steps required until a structure shown in FIG.
In the display region of the liquid crystal display device, the base insulating film 2, the first and second TFTs 6, 7, and the first interlayer insulating film 8 are formed on the TFT substrate 1 by the same method as described in the first embodiment. Form. Further, the data wiring 9a, the gate wiring 9b, and the source wiring 9c connected to the first TFT 6 are formed on the first interlayer insulating film 8, and the counter data wiring 10a and the gate connected to the second TFT 7 at the same time. A wiring 10b and a source wiring 10c are formed.
[0057]
Next, a second interlayer insulating film 11 made of silicon nitride is formed on the first interlayer insulating film 8, the data wiring 9c, etc., and then the second interlayer insulating film 11 is patterned by a photolithography method. The first via hole 41 is formed on the source wiring 9 c connected to the first TFT 6, and at the same time, the second via hole 42 is formed on the source wiring 10 c connected to the second TFT 7.
[0058]
Further, an ITO film having a thickness of 100 nm is formed in the first and second via holes 41 and 42 and on the second interlayer insulating film 11. Then, by patterning the ITO film by a photolithography method, the pixel electrode 43a connected to the source layer 3s of the first TFT 6 through the first via hole 41 is formed, and at the same time, in the second via hole 42 and in the periphery thereof. A connection terminal 43b is formed.
[0059]
Next, a molybdenum (Mo) film is formed on the pixel electrode 43a, the connection terminal 43b, and the second interlayer insulating film 11 by sputtering to a thickness of 2 μm, and then CF_FourAnd O₂The Mo film is patterned by a photolithography method using a mixed gas and a resist pattern to leave the conductive spacers 44 only on the connection terminals 43a as shown in FIG.
A conductive resin may be used instead of the Mo film. In this case, a conductive resin is applied by spin coating, and this is patterned to form a conductive spacer 44. Next, steps required until a structure shown in FIG.
[0060]
After the base insulating film 45 made of silicon oxide is formed on the counter substrate 17 made of glass, a black matrix 46 surrounding the pixel region is formed on the base insulating film 45.
Subsequently, after a color filter 47 and an ITO film 48 are sequentially formed on the black matrix 46 and the base insulating film 45, the color filter 47 and the ITO film 48 are patterned to be separated between the pixel regions, thereby The isolated ITO film 48 is used as an individual counter electrode.
[0061]
Then, the counter substrate 17 and the TFT substrate 1 are bonded to each other in the outer peripheral region with a sealant (not shown) so that the individual counter electrode 48 and the pixel electrode 43a face each other with a gap. This bonding is performed at a position where the conductive spacer (column) 44 contacts the individual counter electrode 48 on a one-to-one basis. A liquid crystal 18 is sealed between the TFT substrate 1 and the counter substrate 17 before or after the substrates are bonded together.
[0062]
The pixel region of the liquid crystal display device described above also has a circuit configuration as shown in FIG. 7A, and a data signal as shown in FIG. 7B is applied to the pixel electrode 36a and the individual counter electrode 36b. . As a result, the pixel drive power supply needs only half of the conventional voltage, and the power consumption becomes smaller than the conventional one.
Further, since the conductive spacer 44 connecting the second TFT 7 and the individual counter electrode 48 functions as a spacer between the TFT substrate 1 and the counter substrate 17, a normally used spherical insulating spacer is omitted. Also gets better.
[0063]
By the way, a structure in which a microcapsulated liquid crystal is sandwiched between the TFT substrate 1 and the counter substrate 17 may be employed, and when the structure is formed, the following steps are performed.
First, in the state shown in FIG. 16A, a photocurable polymer mixed with liquid crystal is spin-coated on the pixel electrode 43a, the connection terminal 43b, and the second interlayer insulating film 11, and then photocured. As shown in FIG. 18 (a), the liquid crystal 50 is microencapsulated to form a polymer-dispersed liquid crystal layer 51.
[0064]
Thereafter, as shown in FIG. 18B, the liquid crystal layer 51 is patterned by photolithography to form holes 51a on the connection terminals 43b.
Next, as shown in FIG. 19A, a molybdenum film 52 is formed in the hole 51a and on the liquid crystal layer 51 by sputtering, and then, as shown in FIG. The film 52 is removed from the upper surface of the liquid crystal layer 51. Then, the molybdenum film 52 remaining only in the hole 51a is used as an extraction electrode.
[0065]
After that, as shown in FIG. 20, the counter substrate 17 on which the base insulating film 45, the black matrix 46, the color filter 47, and the individual counter electrode 48 are formed is used, and the pixel electrode 43a and the individual counter electrode 48 form the liquid crystal layer 51. The counter substrate 17 and the TFT substrate 1 are bonded to each other in the outer peripheral region with a sealant (not shown) in a state of facing each other. This bonding is performed at a position where the extraction electrode 52 contacts the individual counter electrode 48 on a one-to-one basis.
[0066]
Note that another metal film or a conductive resin film may be formed instead of the molybdenum film. In the case of using a conductive resin film, it is appropriate to apply the conductive resin film to the liquid crystal layer 51 and the hole 51a by spin coating, and perform etch back or CMP to leave it as an extraction electrode only in the hole 51a. .
When a copper film is used as the metal film, a hole 51a is formed on the connection terminal 43b as shown in FIG. 21 (a), and then the hole 51a is formed in the hole 51a as shown in FIG. 21 (b). A copper film may be formed as the extraction electrode 53 by electrolytic plating.
[0067]
When the unevenness of the surface of the liquid layer 51 is large, the surface of the liquid layer 51 may be polished and planarized by the CMP method after or after the metal film is removed by the CMP method.
In this embodiment, a glass substrate is used as the counter substrate. However, a silicon wafer is used as the counter substrate, a MOSFET is formed on the silicon wafer instead of the second TFT, and an insulating film or the like is further formed thereon. An individual counter electrode may be formed through. Further, the conductive spacer 44 may be formed at a plurality of positions between the counter electrode and the pixel electrode, or may be formed at the same position as the support portions 14a to 14c shown in FIGS. .
[0068]
In the first to fourth embodiments, both the pixel electrode and the individual counter electrode are formed from a light transmissive conductive material, but one of the pixel electrode and the individual counter electrode is formed from a light transmissive conductive material. However, the other may be formed from a metal material.
(Fifth embodiment)
22 and 23 are cross-sectional views illustrating the manufacturing process of the pixel region of the liquid crystal display device according to the fifth embodiment of the present invention.
[0069]
First, steps required until a structure shown in FIG.
On the TFT substrate 1 made of glass, the base insulating film 2, the first and second TFTs 6 and 7, and the first interlayer insulating film 8 are formed by the same method as in the first embodiment, and further the first The first to third contact holes 8a to 8c are formed in the interlayer insulating film 8, and the data wiring 9a, the counter data wiring 10a, the gate wirings 9b and 10b, the source wiring 9c, and the like are further formed on the first interlayer insulating film 8. 10c is formed.
[0070]
Next, a photosensitive polyimide (insulating resin) film 35 is formed on the first interlayer insulating film 8 to a thickness of 1 to 2 μm. Thereafter, the photosensitive polyimide film 35 is exposed and developed to form a first opening 35 a on the source wiring 9 c of the first TFT 6 and a second on the source wiring 10 c of the second TFT 7. The opening 35b is formed.
[0071]
Furthermore, as shown in FIG. 22B, a copper (Cu) layer is embedded in the first and second openings 35a and 35b by a plating method, and the copper layer is connected to the source wiring 9c on the first TFT 6. Is a pixel electrode 36a, and a copper layer connected to the source wiring 10c on the second TFT 7 is used as the individual counter electrode 36b. In this case, each surface of the pixel electrode 35 a and the individual counter electrode 36 b is substantially perpendicular to the surface of the TFT substrate 1.
[0072]
After forming a copper layer in the first and second openings 35a and 35b and the upper surface of the polyimide film 35 by sputtering, the copper layer is removed from the upper surface of the polyimide film 35 by CMP (chemical mechanical polishing) or etch back. Thus, the copper layer may be left only in the first and second openings 35a and 35b.
Next, as shown in FIG. 23, the polyimide film 35 is removed with a solvent, and then the counter substrate 17 and the TFT substrate 1 are formed using the counter substrate 17 having a black matrix 37 and a color filter 38 formed on the upper surface. Stick together. The color filter 38 and the first interlayer insulating film 8 are opposed to each other, and the counter substrate 17 and the TFT substrate 1 are bonded to each other through a sealing material in the outer peripheral region. It should be noted that the distance between the color filter 38 on the counter substrate 17 and the interlayer insulating film 8 on the TFT substrate 1 is equal to or larger than the height of the pixel electrode 36a plus the height of the source wiring 36b.
[0073]
Then, between the TFT substrate 1 and the counter substrate 17, for example, IPS (In-Plane Switching) type liquid crystal is sealed before or after the bonding.
This completes the formation of the basic structure of the pixel region of the liquid crystal display device.
The pixel region of the liquid crystal display device as described above has a circuit configuration as shown in FIG. 7A, and a voltage as shown in FIG. 7B is applied to the pixel electrode 36a and the individual counter electrode 36b. The As a result, the pixel drive power supply is half the conventional voltage.
[0074]
As shown in FIG. 24, for example, the liquid crystal display device of each embodiment described above includes a liquid crystal display panel 60 having pixel electrodes, individual counter electrodes, first TFTs, and the like, and a pixel driving circuit 20 having a data driver and an investigation driver. The peripheral circuit 61 for performing signal processing, timing processing, and the like, and a single power supply circuit 62 are supplied.
[0075]
In the above embodiment, a planar thin film transistor is used as the switching element, but a staggered or inverted staggered thin film transistor may be used. In addition, although one thin film transistor is connected to each of the pixel electrode and the individual counter electrode, a structure in which a plurality of thin film transistors are connected may be employed.
(Supplementary note 1) a first switching element formed for each of a plurality of pixel regions on a first substrate;
A pixel electrode electrically connected to the first switching element;
An individual counter electrode facing the pixel electrode with a gap and formed independently for each pixel region;
A second switching element connected to the individual counter electrode;
A liquid crystal layer sandwiched between the individual counter electrode and the pixel electrode;
A liquid crystal display device comprising:
(Supplementary note 2) The liquid crystal according to supplementary note 1, wherein the second switching element and the individual counter electrode are formed on the first substrate, and the individual counter electrode is supported by a conductive support portion. Display device.
(Appendix 3) A first insulating film formed on the first switching element and the second switching element,
The pixel electrode is formed on the first insulating film and connected to the first switching element through a first hole formed in the first insulating film,
The liquid crystal display device according to appendix 2, wherein the conductive support portion is electrically connected to the second switching element through a second hole formed in the first insulating film.
(Appendix 4) The liquid crystal display device according to appendix 2 or appendix 3, wherein an insulating spacer is formed between the individual counter electrode and the pixel electrode.
(Supplementary note 5) The liquid crystal display device according to any one of supplementary notes 1 to 4, wherein the pixel electrode and the individual counter electrode are formed in parallel to an upper surface of the first substrate.
(Appendix 6) The pixel electrode is formed substantially perpendicular to the upper surface of the first substrate,
The second switching element is formed on the first substrate;
The individual counter electrode is formed substantially perpendicular to the upper surface of the first substrate and is connected to the second switching element.
The liquid crystal display device according to appendix 1, wherein:
(Additional remark 7) The said pixel electrode and the said separate counter electrode are comprised from the metal or conductive resin, The liquid crystal display device of Additional remark 6 characterized by the above-mentioned.
(Supplementary Note 8) A second substrate provided to face the first substrate is provided.
The liquid crystal display device according to appendix 1, wherein the second switching element and the individual counter electrode are formed on the second substrate.
(Supplementary note 9) The liquid crystal display device according to supplementary note 8, wherein each of the first substrate and the second substrate is made of a transparent insulating substrate, and the pixel electrode is made of a transparent conductive film.
(Supplementary note 10) The liquid crystal display device according to supplementary note 8, wherein the first substrate and the second substrate are each made of a transparent insulating substrate, and the individual counter electrode is made of a metal or a transparent conductive film.
(Appendix 11) The second switching element is formed on the first substrate,
The individual counter electrode is formed on a second substrate provided to face the first substrate,
The liquid crystal display device according to appendix 1, wherein the second switching element and the individual counter electrode are electrically connected through a conductive column.
(Supplementary Note 12) A first insulating film formed on the first switching element and the second switching element,
The pixel electrode is formed on the first insulating film and connected to the first switching element through a first hole formed in the first insulating film.
12. The liquid crystal according to claim 11, wherein the conductive column is formed on the first insulating film and connected to the second switching element through a second hole formed in the first insulating film. Display device.
(Supplementary note 13) The liquid crystal display device according to supplementary note 11 or supplementary note 12, wherein the conductive column is formed of metal or conductive resin.
(Supplementary note 14) The liquid crystal display device according to supplementary note 11, wherein the conductive column is formed at a plurality of locations in the gap between the pixel electrode and the individual counter electrode.
(Supplementary note 15) The liquid crystal display device according to any one of supplementary notes 12 to 14, wherein the conductive column has a function as a spacer between the first substrate and the second substrate. .
(Supplementary note 16) The liquid crystal display device according to supplementary note 1, wherein the liquid crystal layer includes a microencapsulated liquid crystal.
(Supplementary note 17) The liquid crystal display device according to supplementary note 1, further comprising a liquid crystal driving circuit for inputting a signal to the pixel electrode and the individual counter electrode with a time difference.
(Supplementary note 18) The liquid crystal display device according to supplementary note 17, wherein a time difference of the signal is the same as a pulse width of the signal.
(Supplementary note 19) The liquid crystal display device according to supplementary note 1, having a single power source.
(Supplementary note 20) forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element and the second switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a film on the pixel electrode and the first insulating film;
Patterning the film to form a second opening on the second switching element;
On the film, individually forming an individual counter electrode electrically connected to the second switching element through the second opening for each pixel region;
Forming a space between the individual counter electrode and the pixel electrode by removing the film;
A method for manufacturing a liquid crystal display device, comprising:
(Supplementary note 21) The manufacture of the liquid crystal display device according to supplementary note 20, further comprising a step of forming an insulating or conductive spacer in a part of a gap between the individual counter electrode and the first insulating film. Method.
(Supplementary note 22) When forming the second opening, a step of forming a third opening in the film on the first insulating film;
Embedding a part of the individual counter electrode as a spacer in the third opening when forming the individual counter electrode;
The method of manufacturing a liquid crystal display device according to appendix 20, further comprising:
(Supplementary note 23) forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a film on the first switching element and the second switching element;
Patterning the film to form a first groove connected to the first switching element and a second groove connected to the second switching element;
A pixel electrode electrically connected to the first switching element is formed by forming a conductive material in the first groove, and the second switching element is formed by forming a conductive material in the second groove. Forming individual counter electrodes that are electrically connected to:
Removing the film to form a space between the individual counter electrode and the pixel electrode;
A method for manufacturing a liquid crystal display device, comprising:
(Supplementary Note 24) A step of preparing a second substrate and bonding the first substrate and the second substrate in a direction sandwiching the pixel electrode, the individual counter electrode, the first switching element, and the phase 2 switching element. ,
24. The method according to appendix 20 or appendix 23, further comprising a step of sealing liquid crystal in the space between the pixel electrode and the individual counter electrode before or after the first substrate and the second substrate are bonded to each other. A method for manufacturing a liquid crystal display device.
(Supplementary Note 25) A step of forming a first switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a second switching element in a pixel region on the second substrate;
Forming a second insulating film covering the second switching element on the second substrate;
Forming a second opening in the second insulating film;
Forming, on each of the pixel regions, an individual counter electrode electrically connected to the second switching element through the second opening on the second insulating film;
Bonding the first substrate and the second substrate in a direction sandwiching the pixel electrode, the individual counter electrode, the first switching element, and the second switching element;
A method of manufacturing a liquid crystal display device, comprising the step of encapsulating liquid crystal in a space between the first substrate and the second substrate before or after the first substrate and the second substrate are bonded to each other.
(Supplementary note 26) forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element and the second switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a conductive pillar on the first insulating film electrically connected to the second switching element through the second opening;
Forming an individual counter electrode for each pixel region on the second substrate;
Bonding the first substrate and the second substrate in a direction in which the individual counter electrode and the pixel electrode face each other, and a tip of the conductive column is connected to the individual counter electrode;
A method for manufacturing a liquid crystal display device, comprising:
(Supplementary note 27) The method for manufacturing a liquid crystal display device according to supplementary note 26, wherein the conductive column is formed by patterning a metal film or a conductive resin film.
(Additional remark 28) It has the process of putting a liquid crystal in the space formed between the said 1st board | substrate and the said 2nd board | substrate before or after bonding the said 1st board | substrate and the said 2nd board | substrate. 27. A method for producing the liquid crystal display device according to 26.
(Supplementary note 29) A liquid crystal layer having a structure in which liquid crystal encapsulated in a polymer is mixed with the polymer is formed on the pixel electrode and the first insulating film,
Forming the conductive pillar in the contact hole after forming a contact hole connected to the second opening in the liquid crystal layer;
27. A method of manufacturing a liquid crystal display device according to appendix 26, comprising:
(Supplementary note 30) The method for manufacturing a liquid crystal display device according to supplementary note 29, wherein the conductive column is formed by a plating method.
[0076]
【The invention's effect】
As described above, according to the present invention, the pixel electrode and the individual counter electrode are formed at an interval for each pixel region between the first substrate and the second substrate, and the first switching element is connected to the pixel electrode. In addition, since the second switching element is connected to the individual counter electrode, the voltage of the power source required for driving the liquid crystal is half that of the conventional one, and the voltage required for the liquid crystal driving circuit can be lowered. become.
[0077]
Accordingly, the power supply connected to the peripheral circuit and the liquid crystal driving circuit can be shared, and the power consumption can be reduced by reducing the voltage applied to the liquid crystal driving circuit, thereby reducing the cost. Can be achieved.
[Brief description of the drawings]
FIG. 1 (a) is a cross-sectional view showing a pixel structure of a conventional liquid crystal display device, FIG. 1 (b) is a circuit diagram of a pixel region of the conventional liquid crystal display device, and FIG. It is a wave form diagram of the data signal input into the conventional pixel electrode.
FIGS. 2A to 2C are cross-sectional views (part 1) showing a process for forming a pixel structure of the liquid crystal display device according to the first embodiment of the present invention. FIGS.
FIGS. 3A to 3C are cross-sectional views (part 2) showing a process for forming a pixel structure of the liquid crystal display device according to the first embodiment of the present invention. FIGS.
FIGS. 4A and 4B are cross-sectional views (part 3) illustrating the formation process of the pixel structure of the liquid crystal display device according to the first embodiment of the invention. FIGS.
FIG. 5 is a cross-sectional view showing a pixel structure of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 6 is a plan view of an individual counter electrode of the liquid crystal display device according to the first embodiment of the present invention.
7A is a circuit diagram of a pixel region of a liquid crystal display device according to an embodiment of the present invention, and FIG. 7B is input to two thin film transistors formed in the pixel region of the present invention. FIG.
FIG. 8 is a cross-sectional view showing another example of the liquid crystal display device according to the first embodiment of the present invention.
9A to 9C are top views of individual counter electrodes of a liquid crystal display device according to a second embodiment of the present invention.
FIGS. 10A and 10B are cross-sectional views (part 1) illustrating a process for forming a pixel structure of a liquid crystal display device according to the second embodiment of the present invention. FIGS.
FIGS. 11A and 11B are cross-sectional views (part 2) illustrating a process for forming a pixel structure of a liquid crystal display device according to the second embodiment of the present invention. FIGS.
FIG. 12 is a cross-sectional view showing a pixel structure of a liquid crystal display device according to a third embodiment of the present invention.
FIGS. 13A and 13B are sectional views (No. 1) showing a process for forming a pixel structure of a liquid crystal display device according to a third embodiment of the present invention. FIGS.
FIGS. 14A to 14C are cross-sectional views (part 2) showing a process for forming a pixel structure of a liquid crystal display device according to the third embodiment of the present invention. FIGS.
FIG. 15 is a cross-sectional view showing a pixel structure of a liquid crystal display device according to a third embodiment of the present invention.
FIGS. 16A and 16B are cross-sectional views illustrating a process of forming a first pixel structure of a liquid crystal display device according to a fourth embodiment of the present invention.
FIG. 17 is a cross-sectional view showing a first pixel structure of a liquid crystal display device according to a fourth embodiment of the present invention.
FIGS. 18A and 18B are cross-sectional views (part 1) showing the formation process of the second pixel structure of the liquid crystal display device according to the fourth embodiment of the present invention; FIGS.
FIGS. 19A and 19B are cross-sectional views (part 2) illustrating the formation process of the second pixel structure of the liquid crystal display device according to the fourth embodiment of the invention. FIGS.
FIG. 20 is a cross-sectional view showing a second pixel structure of a liquid crystal display device according to a fourth embodiment of the present invention.
FIGS. 21A and 21B are cross-sectional views showing another forming process of the second pixel structure of the liquid crystal display device according to the fourth embodiment of the present invention. FIGS.
FIGS. 22A and 22B are cross-sectional views illustrating a process for forming a pixel structure of a liquid crystal display device according to a fifth embodiment of the present invention.
FIG. 23 is a cross-sectional view showing a pixel structure of a liquid crystal display device according to a fifth embodiment of the present invention.
FIG. 4 is a circuit diagram of a liquid crystal display device according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... TFT substrate (1st substrate), 2 ... Base insulating film, 3 ... Polycrystalline silicon film (semiconductor film), 3d ... Drain layer, 3s ... Source layer, 4 ... Gate insulating film, 5 ... Gate electrode, 6 , 7, 23... Thin film transistor (TFT), 8... First interlayer insulating film, 9 a... Data wiring, 10 a. Insulating film, 12 ... pixel electrode, 13 ... polyimide (resin) film, 14 ... pixel electrode, 14a ... support part, 15 ... black matrix, 16 ... color filter, 17 ... counter substrate, 18 ... liquid crystal, 19 ... spacer, 20 DESCRIPTION OF SYMBOLS ... Pixel drive circuit, 21 ... Base insulating film, 22 ... First interlayer insulating film, 24 ... Gate insulating film, 25 ... Gate electrode, 26 ... Semiconductor layer, 26s ... Source layer, 26d ... Drain layer, 27a ... Data Wiring, 27b ... gate wiring, 27c ... source wiring, 28 ... second interlayer insulating film, 29 ... individual counter electrode, 30 ... second interlayer insulating film, 31 ... black matrix, 32 ... third interlayer insulating film, 33 ... Color filter, 35 ... Polyimide (resin) film, 36a ... Pixel electrode, 36b ... Individual counter electrode, 37 ... Black matrix, 38 ... Color filter, 43a ... Pixel electrode, 43b ... Connection terminal, 44 ... Conductive spacer, 45 ... Underlying insulating film, 46 ... Black matrix, 47 ... Color filter, 48 ... Individual counter electrode, 50 ... Liquid crystal, 51 ... Liquid crystal layer, 51a ... Opening, 52 ... Lead electrode, 53 ... Lead electrode.

Claims (10)

A first switching element formed for each of a plurality of pixel regions on the first substrate;
A pixel electrode electrically connected to the first switching element;
An individual counter electrode facing the pixel electrode with a gap and formed independently for each pixel region;
A second switching element connected to the individual counter electrode;
A liquid crystal layer sandwiched between the individual counter electrode and the pixel electrode ;
By applying a pulse voltage to the first switching element and the second switching element by shifting the phase, when the voltage V ₀ is applied to the pixel electrode, ₀ V is applied to the individual counter electrode, A pixel driving circuit for applying a voltage V ₀ to the individual counter electrode when ₀ V is applied to the pixel electrode ;
A liquid crystal display device comprising:   The liquid crystal display device according to claim 1, wherein the second switching element and the individual counter electrode are formed on the first substrate, and the individual counter electrode is supported by a conductive support. The pixel electrode is substantially perpendicular to the top surface of the first substrate;
The second switching element is formed on the first substrate;
The liquid crystal display device according to claim 1, wherein the individual counter electrode is formed substantially perpendicular to the upper surface of the first substrate and is connected to the second switching element. A second substrate provided opposite to the first substrate;
The liquid crystal display device according to claim 1, wherein the second switching element and the individual counter electrode are formed on the second substrate. The second switching element is formed on the first substrate;
The individual counter electrode is formed on a second substrate provided to face the first substrate,
The liquid crystal display device according to claim 1, wherein the second switching element and the individual counter electrode are electrically connected via a conductive column. Forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element and the second switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a film on the pixel electrode and the first insulating film;
Patterning the film to form a second opening on the second switching element;
On the film, individually forming an individual counter electrode electrically connected to the second switching element through the second opening for each pixel region;
Forming a space between the individual counter electrode and the pixel electrode by removing the film ;
By applying a pulse voltage to the first switching element and the second switching element by shifting the phase, when the voltage V ₀ is applied to the pixel electrode, ₀ V is applied to the individual counter electrode, Connecting a pixel driving circuit for applying a voltage V ₀ to the individual counter electrode when ₀ V is applied to the pixel electrode ;
A method for manufacturing a liquid crystal display device, comprising: Forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a film on the first switching element and the second switching element;
Patterning the film to form a first groove connected to the first switching element and a second groove connected to the second switching element;
A pixel electrode electrically connected to the first switching element is formed by forming a conductive material in the first groove, and the second switching element is formed by forming a conductive material in the second groove. Forming individual counter electrodes that are electrically connected to:
Removing the film to form a space between the individual counter electrode and the pixel electrode ;
By applying a pulse voltage to the first switching element and the second switching element by shifting the phase, when the voltage V ₀ is applied to the pixel electrode, ₀ V is applied to the individual counter electrode, Connecting a pixel driving circuit for applying a voltage V ₀ to the individual counter electrode when ₀ V is applied to the pixel electrode ;
A method for manufacturing a liquid crystal display device, comprising: Forming a first switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a second switching element in a pixel region on the second substrate;
Forming a second insulating film covering the second switching element on the second substrate;
Forming a second opening in the second insulating film;
Forming, on each of the pixel regions, an individual counter electrode electrically connected to the second switching element through the second opening on the second insulating film;
Bonding the first substrate and the second substrate in a direction sandwiching the pixel electrode, the individual counter electrode, the first switching element, and the second switching element;
Enclosing a liquid crystal in a space between the first substrate and the second substrate before or after bonding the first substrate and the second substrate ;
By applying a pulse voltage to the first switching element and the second switching element by shifting the phase, when the voltage V ₀ is applied to the pixel electrode, ₀ V is applied to the individual counter electrode, Connecting a pixel driving circuit for applying a voltage V ₀ to the individual counter electrode when ₀ V is applied to the pixel electrode ;
A method for manufacturing a liquid crystal display device, comprising: Forming a first switching element and a second switching element in a pixel region on a first substrate;
Forming a first insulating film covering the first switching element and the second switching element on the first substrate;
Forming a first opening in the first insulating film;
Forming, on each of the pixel regions, a pixel electrode electrically connected to the first switching element through the first opening on the first insulating film;
Forming a conductive pillar on the first insulating film electrically connected to the second switching element through the second opening;
Forming the individual counter electrode for each pixel region on the second substrate, and in a state where the tip of the conductive column is connected to the individual counter electrode in a direction in which the individual counter electrode and the pixel electrode face each other. Bonding one substrate and the second substrate ;
By applying a pulse voltage to the first switching element and the second switching element by shifting the phase, when the voltage V ₀ is applied to the pixel electrode, ₀ V is applied to the individual counter electrode, Connecting a pixel driving circuit for applying a voltage V ₀ to the individual counter electrode when ₀ V is applied to the pixel electrode ;
A method for manufacturing a liquid crystal display device, comprising: Forming a liquid crystal layer having a structure in which a microencapsulated liquid crystal is mixed with a polymer on the pixel electrode and the first insulating film;
Forming the conductive pillar in the contact hole after forming a contact hole connected to the second opening in the liquid crystal layer;
The method of manufacturing a liquid crystal display device according to claim 9, comprising:

Images